Yet more evidence that commercial brewers do not mash at 5.2 to 5.6 pH ...

[hopjuice_71]

Edit: This one threw me a curve ball I can't hit (as in comprehend):


If it says anything to me, it's saying that alpha acids are better solubilized at higher pH's, but once you get them to fully solublize in a low pH environment nothing else will be changed by the lower pH aside from the initial solubilization time. And isomerization must be preceded by solubilization. Can that be what it is saying? Again I must inject that pellet hops solubilize leagues faster than whole/leaf. Are pellets the answer to the negation of slower solubilization due to lower Wort pH?

It was not well articulated, but this is what it means. The isomerization reaction obeys first-order kinetics, which means that the higher the concentration of a-acids, the higher the velocity of the reaction to iso-a-acids. So, higher solubility at low pH means more a-acid, which means more production of iso-a-acids. That is the first part of the sentence. The last part of the sentence reflects that there is no inherent change to the kinetic constant governing the reaction at different pHs. Practically speaking, it seems like a bit of a strange sentence as I believe you would have to get to quite extreme hopping levels to reach solubility limits at boiling temperature, so pH really shouldn't feature much there (maybe possible in the days of the IBU race?).

 

[Robert65]

Was looking at a paper on what I thought was an unrelated topic, ascorbic acid oxidase in mashing, and spotted this little gem of a table showing pH over time in a mash with added ascorbic vs a control mash. Certainly looks like an example of mashes, regardless of the pH established at mashing in any whatever means, converging on a point in the 5.4 ballpark. Just another piece of the puzzle.

 

[Silver_Is_Money]

Due to the ascorbic acid addition I'm not sure this is going to be representative of the typical mash pH trend without ascorbic acid added. It may just show that over time the ascorbic acid is being consumed and transformed into a non acid salt, perhaps at least partially as it reacts with oxygen.

The control hits 5.5 at the 20 minute mash mark (about right where a home brewer will sample it), and then pretty much stays there. If they are precisely measuring pH to 3 decimal places, they must be using some premium equipment. A home brewer with a far less capable pH meter is more likely to read 5.5 at both 20 minutes and 60 minutes. Thus if it trended to a final pH, I'd call it 5.5.

 

[eric19312]

Not of the scientific article caliber @Silver_Is_Money was initially pointing at but came across this presentation which seems reflective of what pro brewers really do. Slides 18-19 confirm the target mash pH of 5.5-5.6 at 20C.
http://www.craftbrewersconference.com/wp-content/uploads/ImprovingBrewhouseEfficiency-Havig.pdf

 

[Silver_Is_Money]

It looks like their best efficiency was being achieved at 5.3 pH as measured at 65 degrees C. (or ~5.6 pH if measured at 20 degrees C.)

 

[hopjuice_71]

It looks like their best efficiency was being achieved at 5.3 pH as measured at 65 degrees C. (or ~5.6 pH if measured at 20 degrees C.)

Yes, a whopping 2% better efficiency when compare to "out of range" Not sure how much I buy into that number being very accurate.

 

[eric19312]

Yes, a whopping 2% better efficiency when compare to "out of range" Not sure how much I buy into that number being very accurate.

I dunno. They were aiming at helping their worst brewers who were at about 82% efficiency to perform more like their best performers who were at about 89-90% efficiency (total 7-8% difference). Seems like pH could account for about 25% of the overall gap while the remainder of the distance to the goal was due to crush.

The presentation provides insight into how pro brewers think and what they do about it. These brewers clearly do think 2% efficiency improvement matters and they do recommend testing pH to save that 2%.

Obviously 2% just doesn't matter on homebrew scale but the point of the thread is what pH do pro brewers mash at.

 

[Robert65]

...but the point of the thread is what pH do pro brewers mash at.

Hey, that should be in the title of the thread... [emoji38]

 

[Qhrumphf]

I dunno. They were aiming at helping their worst brewers who were at about 82% efficiency to perform more like their best performers who were at about 89-90% efficiency (total 7-8% difference). Seems like pH could account for about 25% of the overall gap while the remainder of the distance to the goal was due to crush.

The presentation provides insight into how pro brewers think and what they do about it. These brewers clearly do think 2% efficiency improvement matters and they do recommend testing pH to save that 2%.

Obviously 2% just doesn't matter on homebrew scale but the point of the thread is what pH do pro brewers mash at.

Whoa.....It's almost like some times pros do things because it makes better beer...

...And other times they do things because it makes cheaper beer.

 

[eric19312]

Whoa.....It's almost like some times pros do things because it makes better beer...

...And other times they do things because it makes cheaper beer.

pros ... it's a business right? thats what pro means...

 

[Qhrumphf]

pros ... it's a business right? thats what pro means...

Guess depends on whether you're asking the brewer or the accountant lmao

In seriousness I sense most folks in this thread (as in I haven't seen anything to suggest otherwise) are well aware of the distinction between maximizing quality and minimizing cost, but it's important to not lose the forest through the trees.

 

[TheHopfather]

So what are you guys doing in order to calculate the acid addition in the boil? I like the ideas in this thread and would like to give it a shot, just curious if there is an easy way to calculate the acid addition after the mash is complete. Are you just adding acid, checking pH and adjusting until you hit 5.1 ~ 5.2 pH in the boil?

 

[Silver_Is_Money]

So what are you guys doing in order to calculate the acid addition in the boil? I like the ideas in this thread and would like to give it a shot, just curious if there is an easy way to calculate the acid addition after the mash is complete. Are you just adding acid, checking pH and adjusting until you hit 5.1 ~ 5.2 pH in the boil?

There are assuredly other methods, but I've incorporated "Kettle pH Made Easy" within "Mash Made Easy". The kettle pH adjustment is thereby done for you within this sheet found within 'MME', and the process is simple, easy, and (hopefully) quite intuitive to understand. Plus it's free.

 

[Robert65]

The calculator mentioned is more sophisticated, and is very easy to use out of the box, but I have long used a quick and dirty, back of the envelope, method, empirically dialed in, that works for me. Others could do the same sort of empirical development if they wish.

I started with some values for the buffering capacity of wort as determined by Kolbach, based on the original weight of grist (the residual buffering of which is what needs to be overcome,)* which are cited variously but run around 32 mEq/(pH • kg). Observing results over numerous batches, I determined that my worts can be assumed to be well represented by an approximation of 30 mEq/(pH • kg). Using lactic acid 88%, I round off its normality, at pH 5.4, to 11 mEq/ mL. The natural drop in pH during the boil varies, but my longtime observation is that it is typically about 0.1 units, in practice, under conditions in my brewery (this is also consistent with Kunze's statements.) So this leads me to a simple formula: (desired delta pH - 0.1) * grist in kg * 30 / 11 = mL lactic acid 88% required. This gets me as close as anything else, but YMMV, as it is, as I said, based in part on empirical refinement of my original assumptions derived from the available literature.

*I use actual grist weight. Kettle pH Made Easy ingeniously generates an "effective grist weight" based on volume and gravity. The relative virtues of these approaches has, I believe, been discussed elsewhere on these boards.

 

[TheHopfather]

@Silver_Is_Money ah, okay so its inside Mash Made Easy. It sounded like you were beta testing a separate version elsewhere. I typically use BruNWater so I'm not super familiar with yours, I'll give it a shot.

@Robert65 just so I've got this right, your formula would like look something like this (assuming 5.65 pH in the mash and a 5.8 kg grist);

((5.65 - 5.10) - 0.1) * 5.8kg * 30/11 = 7.12 mL?

Edit: I'm still a bit confused as the kettle pH adjustment. Are we shooting for 5.0 ~ 5.1 at room temp, or adjusting similar to mash temp so we'd be reading 5.40-ish at room temp? You'd think after 295 posts I'd have figured that part out.

Edit 2: I opened up MME, it says 5.0 ~ 5.2 pH for the COOLED beer. Makes sense now. Edited my formula example.

 

[Robert65]

@TheHopfather, yes that's how I calculate it. Again, I've incrementally tweaked the values for buffering and pH drop in the boil until the formula matched actual results I was getting to within +/- 0.05 units. But it works as well for me as a more sophisticated approach like the one in MME, probably because there are still things we don't understand, and I dont know how specific to my process and its idiosyncrasies my formula's success might be. MME does offer the convenience of multiple choices for acid, and selections for sg/Plato and metric or US units. What I find convenient about my approach is that I don't have to have an accurate preboil volume measurement, which I usually don't have. While my formula and MME may generate slightly different recommendations for quantity of acid, any resulting kettle pH difference is negligible; again, there's probably much about wort buffering we still don't fully understand. (Full disclosure, I was one of the beta testers on the tool in MME.)

 

[mabrungard]

The buffering of kettle wort is the same as mash wort. You can calculate the amount needed by checking how much acid is needed to drop your mash pH to the level you want as if were in the mash tun. Of course, this assumes that the sparging water has been properly neutralized to near zero alkalinity.

 

[TheMadKing]

The buffering of kettle wort is the same as mash wort. You can calculate the amount needed by checking how much acid is needed to drop your mash pH to the level you want as if were in the mash tun. Of course, this assumes that the sparging water has been properly neutralized to near zero alkalinity.

Thanks for confirming Martin, that's the assumption I was working off of for using Bru'n water for kettle pH adjustment.. Glad to know it wasn't a terrible idea

 

[hopjuice_71]

I dunno. They were aiming at helping their worst brewers who were at about 82% efficiency to perform more like their best performers who were at about 89-90% efficiency (total 7-8% difference). Seems like pH could account for about 25% of the overall gap while the remainder of the distance to the goal was due to crush.

The presentation provides insight into how pro brewers think and what they do about it. These brewers clearly do think 2% efficiency improvement matters and they do recommend testing pH to save that 2%.

Obviously 2% just doesn't matter on homebrew scale but the point of the thread is what pH do pro brewers mash at.

Sure, but where did that number come from? An average? How do we know it wasn't 2% but with +/- 4% error?

...yes I am a nerdy scientist.

 

[eric19312]

Sure, but where did that number come from? An average? How do we know it wasn't 2% but with +/- 4% error?

...yes I am a nerdy scientist.

OK again...how many professional brewers are hard core scientists? Primary qualification for getting into the field seems to be ability to lift a 50 lb sack of grain and a love of cleaning stainless steel.

 

[Big Monk]

OK again...how many professional brewers are hard core scientists? Primary qualification for getting into the field seems to be ability to lift a 50 lb sack of grain and a love of cleaning stainless steel.

^^^^
THIS.

In talks with many, many people who are industry insiders and industry adjacent, a shocking amount of professional brewers know very little about the nuts and bolts of brewing science.

Only a small percentage of professional brewers (i'm thinking of the Dan Careys and the like) in our country are actually formally trained and well versed in the science of the matter.

Like you said, they are way too busy cleaning and, frankly speaking, it doesn't matter to me so long as the beer is good. Too often it's not so it makes it very easy to spot those who really take the science and apply it.

That's really the big thing: Applied Brewing Science. I don't expect everyone to know the theory but you should know enough for practical application.

 

[Qhrumphf]

OK again...how many professional brewers are hard core scientists? Primary qualification for getting into the field seems to be ability to lift a 50 lb sack of grain and a love of cleaning stainless steel.

This guy gets it.

 

[Die_Beerery]

The buffering of kettle wort is the same as mash wort

Actually, it's half. The grain/husks acts as a buffer.

Sources Kunze, Narziss, and my very exact (down to .1ml) dosage graphs in process.

 

[mabrungard]

That’s not my experience, but it’s possible. Could you pinpoint the reference in Kunze? I’d like to review that. I’m skeptical since any buffering power from the grain/husk would already be in the wort by the end of the mash and the kettle wort would be the same chemistry.

 

[Big Monk]

That’s not my experience, but it’s possible. Could you pinpoint the reference in Kunze? I’d like to review that. I’m skeptical since any buffering power from the grain/husk would already be in the wort by the end of the mash and the kettle wort would be the same chemistry.

The “shoot from the hip” answer would be the requirement for biological acid between the mash and kettle which is described in the wort production chapter of Kunze (V5 - Chapter 3?) as being 60 ml/kg and 30 ml/kg respectively.

I have to imagine there is a reason for dosing 50% less Sauergut in the kettle and my first thought is a difference in buffering of the solution.

 

[Brewsader1]

The “shoot from the hip” answer would be the requirement for biological acid between the mash and kettle which is described in the wort production chapter of Kunze (V5 - Chapter 3?) as being 60 ml/kg and 30 ml/kg respectively.

I have to imagine there is a reason for dosing 50% less Sauergut in the kettle and my first thought is a difference in buffering of the solution.

I've been following this thread and really enjoying it. As I read the last two comments, I had just started my boil on 10 gal of festbier (75% pils/25% munich, both barke). Based on bru'nwater 5_5, I hit my mash pH (room temp) at 5.55 as planned.

Granted this is one case, but I took the 88% lactic acid amount needed to drop mash the pH to 5.38 based on the spreadsheet, which was 2.6 mL and added to the boil. After adding that quantity to the boil 30 minutes in, I took a sample 5 minutes later and cooled it to room temp. The pH reading was 5.38. Then with 10 minutes left, I put in another 4.7 mL of 88% lactic. The Bru'nwater spreadsheet predicted a mash pH of 5.15. It's currently sitting at 5.12.

I mashed with 14.5 gallons with 1.75 sparge because I couldn't fit all strike water in the mash tun. So in one case, my experience today agrees with Martin's.

 

[Robert65]

Kunze places the buffering capacity of the mash at 64 mEq/(pH • kg) and of the cast wort at 32. My experience tells me that both are actually in the 32 range, that is that, as Martin suggests, there is probably not a 2:1 relationship, but actual values TBD.

 

[brewbama]

Kunze places the buffering capacity of the mash at 64 mEq/(pH • kg) and of the cast wort at 32. My experience tells me that both are actually in the 32 range, that is that, as Martin suggests, there is probably not a 2:1 relationship, but actual values TBD.

Would malt variables make a difference in buffering capacity?

Is the mash he used to develop his position any different that the mash you and Martin are using to develop yours? Could be you’re all correct.

...or are variables such as barley variety, method of malting, grist bill, etc a red herring?

 

[Brewsader1]

Would malt variables make a difference in buffering capacity?

Is the mash he used to develop his position any different that the mash you and Martin are using to develop yours? Could be you’re all correct.

...or are variables such as barley variety, method of malting, grist bill, etc a red herring?

A mash pH estimate, regardless of which format/spreadsheet/etc, is going to be a model based on everything in the water that impacts pH as well as how the malt impacts the pH. So variability in the grain Bill and water is going to reflect how accurate of a model it is, but I suspect the same guiding principles (aka whether a portion of buffer is left behind in the mash vs all buffer going to the boil) are going to apply regardless of grain bill and water changes from batch to batch.

 

[brewbama]

[emoji106]

 

[Silver_Is_Money]

If all else that went into a recipe is identical, and brewer A measures 85% efficiency, while brewer B measures 60% efficiency, it does not seem very likely that both of their post lauter worts (downstream and now fully dissociated from the original grist) will both buffer at the same value, or that they will both buffer in 100% lock step relation to the starting grist weight. It seems far more intuitive that wort specific gravity should have a noticeable impact upon wort buffering downstream from the grist. And for that matter, it may also have a serious impact on buffering even while the wort and grist are still linked during the mash.

 

[Silver_Is_Money]

A mash pH estimate, regardless of which format/spreadsheet/etc, is going to be a model based on everything in the water that impacts pH as well as how the malt impacts the pH.

I always throw up a red flag when I see the word "everything". as if every single interrelationship between every molecule within a recipe and process is understood such that it can be highly accurately modeled. I contend that there is much that remains unknown, or misunderstood, or both.

 

[Robert65]

We don't know how the declaration Kunze made was arrived at, what his sources or their methods were. But if somebody showed that half the buffering is left behind in the mash, and nobody else sees this happening, something's whack.

 

[Brewsader1]

I always throw up a red flag when I see the word "everything". as if every single interrelationship between every molecule within a recipe and process is understood such that it can be highly accurately modeled.

Ok, fine. “Known ions in the water where an effect can be estimated.” Which if you are you using distilled and (for the most part RO), this is everything.

 

[Brewsader1]

If all else that went into a recipe is identical, and brewer A measures 85% efficiency, while brewer B measures 60% efficiency, it does not seem very likely that both of their post lauter worts (downstream and now fully dissociated from the original grist) will both buffer at the same value, or that they will both buffer in 100% lock step relation to the starting grist weight. It seems far more intuitive that wort specific gravity should have a noticeable impact upon wort buffering downstream from the grist. And for that matter, it may also have a serious impact on buffering even while the wort and grist are still linked during the mash.

I agree, but just as much as this impacts the pH impact of acid additions to the boil kettle, this efficiency would also impact your mash pH. So if you have a highly accurate model, then these efficiencies should already be considered as part of it, right? And therefore it comes back to the transfer of buffering material from mash tun to bk. I may be misunderstanding, though.

 

[Silver_Is_Money]

I agree, but just as much as this impacts the pH impact of acid additions to the boil kettle, this efficiency would also impact your mash pH. So if you have a highly accurate model, then these efficiencies should already be considered as part of it, right? And therefore it comes back to the transfer of buffering material from mash tun to bk. I may be misunderstanding, though.

No, I don't believe that you are misunderstanding. What I contend is that no one has an accurate model, let alone highly accurate. The efficiencies are not ever part of it, sans for an admittedly early (and likely flawed to some degree in more ways than one) attempt at this found within Kettle pH Made Easy.

 

[Die_Beerery]

I've been following this thread and really enjoying it. As I read the last two comments, I had just started my boil on 10 gal of festbier (75% pils/25% munich, both barke). Based on bru'nwater 5_5, I hit my mash pH (room temp) at 5.55 as planned.

Granted this is one case, but I took the 88% lactic acid amount needed to drop mash the pH to 5.38 based on the spreadsheet, which was 2.6 mL and added to the boil. After adding that quantity to the boil 30 minutes in, I took a sample 5 minutes later and cooled it to room temp. The pH reading was 5.38. Then with 10 minutes left, I put in another 4.7 mL of 88% lactic. The Bru'nwater spreadsheet predicted a mash pH of 5.15. It's currently sitting at 5.12.

I mashed with 14.5 gallons with 1.75 sparge because I couldn't fit all strike water in the mash tun. So in one case, my experience today agrees with Martin's.

I don't believe this should be used a reference. Brunwater does not model Munich well, or really pils for that matter. Let me explain.. If I'm not mistaken, brunwater "pils" has a pH of 5.7? and I can pretty much guarantee the barke pils is around ~5.85. Also munich malt is a tricky malt that is acidic, and should be more so modeled as a medium "cara" malt. So with those two things you "hit" your mash pH because the barke pils is higher and the munich is lower arriving you in the middle.

 

[Die_Beerery]

We don't know how the declaration Kunze made was arrived at, what his sources or their methods were. But if somebody showed that half the buffering is left behind in the mash, and nobody else sees this happening, something's whack.

I trust my data, because its made by professional instruments and computers, as for others....

 

[Brewsader1]

I don't believe this should be used a reference. Brunwater does not model Munich well, or really pils for that matter. Let me explain.. If I'm not mistaken, brunwater "pils" has a pH of 5.7? and I can pretty much guarantee the barke pils is around ~5.85. Also munich malt is a tricky malt that is acidic, and should be more so modeled as a medium "cara" malt. So with those two things you "hit" your mash pH because the barke pils is higher and the munich is lower arriving you in the middle.

Totally get that, and that’s why I said it’s just one data point. Yes the pils was I think 5.84 from the lot info. I didn’t increase the color, but I did list Munich as a crystal malt in the grain bill. And I know the spreadsheet may not be the most accurate one, but given this whole thread, it helps me get to about where I’m shooting and then I can manually adjust from there. Which in yesterday’s case, bru’nwater got me there.

 

[Big Monk]

One of the biggest caveats we have when discussing this stuff is standardization.

We like phrases like, "In my experience...", "My data says...", "In my brewery...", etc. but it becomes really hard to nail down the finer points from person to person, especially when discussing things in a forum.

I am certainly biased due to my close connection with @Die_Beerery, and I have spent many hours working through troubleshooting with him, trying and testing things remotely in regards to his brewery, etc. but I can say that I trust the level of consistency and standardization going on at The Beerery.

What it has shown me is that we can generally trust his data for his batches on his system and that much of that data matches pretty closely to academic and professional literature.

Now that doesn't mean anyone else's data is bunk, but as has been stated, sometimes factors unknown to the brewer (DI pH differences to actuals, etc. as described above, Munich as Cara, modelling of source water, etc.) cause things to appear one way when they are actually another way.